<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>3D</title>
    <style>
        .box{
            width: 500px;
            height: 500px;
            border: 5px solid black;

            transform-style: preserve-3d;
            /*flat:2d舞台*/
            /*preserve-3d:构建一个3d舞台*/
            position: relative;
            margin: 0 auto;

            /* transform:rotateY(0deg); */
            /* 添加景深 */
            perspective: 900px;
        }
        .center{
            position: absolute;
            /* 添加绝对定位 */
            width: 200px;
            height: 200px;
            background: red;
            left: 50%;
            top: 50%;
            margin-left:-100px;
            margin-top:-100px;


            transform:translateZ(100px);
            /* transform:translate3d(0,0,0); */


        }
    </style>
</head>
<body>
    <div class="box">
        <div class="center"></div>
    </div>
</body>
</html>